[Osaka Daigaku shigaku zasshi] The journal of Osaka University Dental Society最新文献

The joining procedure for uniting metal structures is very important in the dental clinic, and various kinds of metal joining methods have been performed for clinical application. The conventional torch soldering method using a blow torch has been generally adopted. However, it has several clinical problems, especially in the construction of removable partial dentures. The base metal wires made of a chromium-cobalt alloy are subject to changes in their mechanical properties caused by heating, when wrought wire clasps are joined to rests or frameworks. In addition to the flexibility of wrought wire clasps, damage to acrylic resin denture bases and acrylic resin teeth occurs in the repair of removable partial dentures. In this paper, the electric resistance welding and soldering methods were applied to attach wrought wire components to a removable partial denture framework to resolve the problems of the torch soldering method. As a result, it is suggested that these electric resistance welding and soldering methods have the following advantages, as compared with the conventional torch soldering method. 1. When using this electric resistance welding method, it is possible to fix metals temporarily to each other more securely and strongly than the conventional temporary fixation methods using sticky wax or acrylic resin. 2. The electric resistance soldering method does not require any heat insulation or a partition as the torch soldering method does, because the soldered area is only heated partially. 3. In the case of soldering electrically wrought wire clasps to metal structures such as rests and connectors, there is no fear of of overheating a wide area of wires.(ABSTRACT TRUNCATED AT 250 WORDS)

Leukocytosis associated with malignant disease has been known as a paraneoplastic syndrome and occurs occasionally in patients with oral malignancies. In this study, mechanisms underlying leukocytosis associated with malignancy was investigated, using a squamous cell carcinoma of the maxilla from a patient who manifested marked leukocytosis. When the patient's tumor was inoculated into nude mice, it formed squamous cell carcinoma (MH85) and induced leukocytosis and splenomegaly. Leukocytosis and splenomegaly paralleled tumor growth. Surgical excision of MH85 tumor resulted in a dramatic reduction of leukocyte count and spleen weight, indicating an involvement of humoral mediators released by MH85. MH85 cells conditioned medium (MH85CM) were shown to contain granulocyte-colony stimulating factor (G-CSF) activity, which is a potent growth factor specific for granulocytes. These results suggest G-CSF or G-CSF like substance secreted by MH85 cells is responsible for leukocytosis in MH85 bearing nude mice (MH85 mice) and in the patient. MH85 cell growth was stimulated by G-CSF and inhibited by anti-G-CSF antibody, thus suggesting that G-CSF like substance is a autocrine growth factor for MH85 cells. Splenectomized MH85 mice developed less severe leukocytosis than did non-splenectomized mice. This finding indicated that not only G-CSF like substance secreted by MH85 cells but other humoral factors released by the hyperplastic spleen contribute to the development of leukocytosis. Splenic monocytes derived from MH85 mice and MH85CM-stimulated splenic monocytes showed increased secretion of tumor necrosis factor (TNF) and interleukin-1 (IL-1), both of which have been reported to induce neutrophilia in animals. Moreover, injection of anti-TNF-antibody into neutrophilic MH85 mice significantly, although not completely, decreased leukocyte count. Thus, it seemed likely that increased secretion of TNF and IL-1 by spleen cells that are stimulated by humoral factors released from MH85 also contributes to the progression of leukocytosis. In splenectomized mice, enlargement of MH85 tumor was retarded and metastases were impaired compared these in nonsplenectomized mice. Coculture of splenocytes from MH85 mice with normal spleen cells, inhibited blastogenesis in response to mitogen. The result suggests that splenocytes from MH85 mice played as immune suppressive cells. MH85CM conferred immune suppressive activity on normal spleen cells. This suppressor cell-inducing factor (SCIF) in MH85CM was found to have an apparent molecular weight of approximately 25kd, and its biological activity was neutralized by anti-G-CSF antibody. Therefore, SCIF secreted by MH85 cells was likely to be G-CSF like substance.(ABSTRACT TRUNCATED AT 400 WORDS)

By the recent development of new ceramics, i.e. castable glass ceramics and high strength porcelain, the clinical use of all-ceramic bridges as well as all-ceramic crowns have been expected. The purpose of this study was to evaluate the mechanical properties of new ceramics and to analyze the stress distributions in new ceramic crowns and bridges. The Young's modulus, flexural strength and diametral tensile strength of four types of new ceramics (DICOR, BIORAM-C, OPTEC, and HI-CERAM) were measured, and the fracture loads of new ceramic anterior crowns and bridges on the metal abutments were evaluated. Three dimensional finite element analyses of new ceramic anterior crowns and bridges were also carried out to investigate the effects of various mechanical factors; locations of loading point, types of ceramics, thickness of crowns, luting materials, core materials, and designs of fixed joints. In each experiment, the loading forces were applied at 45 degree to the tooth axis. The results were summarized as follow; 1) DICOR showed the highest flexural strength. HI-CERAM hard core porcelain showed the highest Young's modulus and tensile strength. 2) HI-CERAM crowns showed the highest fracture load among the new ceramic crowns. DICOR bridges were significantly stronger than BIORAM-C bridges. The stress analyses of the experimental cases indicated that the fractures of crowns and bridges occurred by the concentration of tensile stresses. 3) By the load at the incisal edge, the highest tensile stresses were caused in the crown. In the crown with 0.5 mm thickness at axial wall, high tensile stresses were observed at more wide regions of palatal side than in the crown with 0.75 mm or 1 mm thickness. However, in the case with an enamel layer remained on the surface of the abutment tooth, the stresses were reduced in spite of the crown thickness. When the abutment tooth was restored with a metal post and core, the stresses of the crown decreased in comparison with the natural abutment tooth. 4) In case of bridges, high tensile stresses concentrated at the fixed joints under any loading point. The stresses tended to rise slightly according to the increase of the Young's modulus of bridges. The aluminous core material which had high Young's modulus was effective for the reduction of the stresses at the surface of the bridge. Those tensile stresses were reduced remarkably by increasing the thickness of the fixed joints toward the labial and vertical side.(ABSTRACT TRUNCATED AT 400 WORDS)

A patient with obstructive sleep apnea has been treated by means of a mandibular repositioning appliance made of silicone rubber. The patient is a male and 54 years old with a slim body and complained a excessive daytime sleepiness and unsatisfied sleep. A lateral head plate revealed retruded mandible and narrow A-P diameter in the lower part of oropharynx. Moderate frequency of apnea was found in the initial all-night polysomnographic recording. The mandible has been brought forward by 5 mm and downward by 11 mm, which enlarges the diameter of oropharynx anterio-posteriorly by 2-3 mm. Since the appliance has been inserted during bed-time, the daytime sleepiness and unsatisfied sleep has been eliminated. The second polysomnographic recording revealed significant increment of deep NREM sleep and REM sleep and decrement of arousal during sleep after insertion of the appliance. It is indicated, therefore, that the application of the mandibular repositioning appliance is one of the effective methods for the treatment of obstructive sleep apnea.

Cryosurgery provides two prominent features, that is in situ destruction of malignant tumor and potential immunotherapy against tumor. In order to investigate the immunological response after cryosurgery, immunological system of macrophage activation were studied in an experimental tumor system using BALB/c mice and syngeneic Meth-A fibrosarcoma. The mice inoculated the cryodestroyed Meth-A (Cryo-Meth-A mice) acquired antitumor potency in Meth-A challenge test, and the mice inoculated the Mitomycin C treated Meth-A (MMC-Meth-A mice) also acquired antitumor potency. Spleen cells of Cryo-Meth-A mice showed antitumor activity in Winn assay, and spleen cells of MMC-Meth-A mice also showed antitumor activity. The effector cells in Cryo-Meth-A mice were mainly macrophages and natural killer (NK) cells. On the other hand, they were mainly macrophages and cytotoxic T lymphocytes (CTL) in MMC-Meth-A mice. The maximum macrophage cytostatic activity of Cryo-Meth-A mice was noted on 14 days after inoculation (Day 14), whereas it appeared on Day 7 and continued until Day 14 in MMC-Meth-A mice. Macrophages of Cryo-Meth-A mice enhanced the production activity of interleukin 1 (IL-1), interferon (IFN) and prostaglandin E2 (PGE2). On the other hand, macrophages of MMC-Meth-A mice enhanced production activity of tumor necrosis factor (TNF) and increased Ia antigen positive ratio. These findings suggest that macrophages of both groups are activated by different immunological mechanisms. It was found that Cryo-Meth-A played a role as an alpha-IFN inducer, and the macrophages stimulated with Cryo-Meth-A produced alpha-IFN in vitro. Intraperitoneal (i.p.) administration of the anti-alpha-IFN antibody carried down-regulation of macrophage cytostatic activity and NK activity of Cryo-Meth-A mice, whereas MMC-Meth-A mice were not. In addition to these findings, CTL activity enhanced some extent by i.p. administration of the anti-alpha-IFN antibody. These facts suggest that the alpha-IFN have two ways of immunological regulation, the first one is the activation of macrophage cytostatic activity and NK activity, and the other is down-regulation of CTL activity by suppression of Ia antigen expression of macrophages. These results suggest that cryodestruction changes the tumor antigen of Meth-A cells, thereby Cryo-Meth-A induces peculiar immunological response.

Studies have been undertaken to apply CAD/CAM system to Dentistry and to make prosthetic appliances with this system automatically. Specimens are 4 times large plaster models. For the inside of the crown, the plaster model of prepared tooth is measured with laser displacement meter then the numerical data is obtained. After modification of this data for the concave cutting, the modeling machine works with this numerical data. For the outside of the crown, the typical colonal figure data (= CAD Data Base) is prepared. And this data is modified with computer to fit the prepared tooth margin and proximal or antagonical tooth (= CAD). This CAD Data Base was obtained with 3 dimensional point digitizer (3DPD). Because this measuring method with 3DPD is to be able to select points, the CAD Data Base could be consists of characteristic points. When this data base is really used, it is interpolated with s-spline. Spline interpolation is indispensable to the CAD/CAM system. Further understanding of this system, explanation is divided into three parts which are 3D measurement, CAD and CAM. (3D measurement) Two types of 3D measurement is dealed with this system. One is for the CAD data base and another is for the prepared tooth model. 3D measurement of the prepared tooth model is equivalent of the impression takings in the routine method. For the clear marginal line and for the uniform distribution of measuring points, the prepared tooth model is tilted and rotated on the working table when it is measured with laser. (CAD) The CAD Data Base can be extended, contracted, parallel translated and rotated with the Affine transformation. For putting the individual margin data on the CAD Data Base, the prepared tooth margin is re-digitized with 3DPD. Occlusal data is taken from F.G.P. core. (CAM) The application of the spline interpolation to the tool offset theory, which is effective at the groove especially, makes easy to calculate the tool path. When the prepared tooth model is manufactured, it is tilted and rotated on the table like the measurement with laser-scan.

Statistical studies on numerical anomalies using orthopanthomograms had been attempted. In this paper, congenital coexistence of hyperdontia and hypodontia in individuals had been researched using 4009 orthopanthomograms of pedodontic patients. The tested were following; Male: Age 2-5 1036, 6-11 905, 12-22 Total 1963. Female: Age 2-5 1032, 6-11 985, 12-29 Total 2046. respectively. And 11 (male: 7, female: 4) coexistence cases were found. They were combinations of a hyperdontia (1 tooth: 5, 2 teeth: 2, 3 teeth: 1, 4 teeth: 2, 7 teeth 1) and a hyperdontia (1 tooth or 2 teeth).

To investigate the participation of neuropeptides present in the peripheral endings of primary afferent neurons in the inflammatory response, immunoreactive substance P (iSP), calcitonin gene-related peptide (iCGRP) and neurokinin A (iNKA) levels in the s.c. perfusate, and inflammatory response (edema and plasma protein extravasation) evoked in rat paw by noxious stimulation were determined. The effects of these peptides on plasma protein extravasation in the skin of the hind paw of mice were also examined with the pontamine sky blue protein labelling method. The following results were obtained. 1) Immersion of the rat hind paw for 30 min into hot water adjusted to 47 degrees C led to a marked increase in the release of iSP and iCGRP in the subcutaneous perfusate with the formation of thermal edema. 2) Mechanical stimulation (600 g, 10 min) to the hind paw or electrical stimulation of the saphenous and sciatic nerves (10 V, 2 Hz, 1msec duration, 10 min) evoked the increase of iSP release in the perfusate with plasma protein extravasation. 3) iNKA release was not affected by neither heat nor mechanical stimulation. 4) Intraplantar injection of SP, CGRP and NKA induced plasma protein extravasation, the order of potencies being SP greater than CGRP greater than NKA. The action of SP was antagonized by spantide, an SP antagonist. The injection of CGRP with SP produced a synergistic action on plasma protein extravasation. 5) Neonatal pretreatment with capsaicin, which is known to degenerate small-diameter primary afferent neurons, caused the decrease in amount of iSP and iCGRP released during noxious heat stimulation. 6) Pretreatment with Compound 48/80, or stem bromelain and emorphazone, or des-Arg9-[Leu8]-BK, inhibited the iSP release evoked by noxious heat stimulation. 7) Opioids such as morphine (mu-agonist) and ethylketocyclazocine (kappa agonist) inhibited the heat stimulus-evoked iSP release and thermal edema, and the inhibitory effects were antagonized by pretreatment with their antagonists. 8) Morphine or ethylketocyclazocine or [D-Ala2,D-Leu5]-enkephalin (delta-agonist) inhibited the release of iSP evoked by electrical stimulation of the saphenous and sciatic nerves. These results indicate that SP and CGRP present in peripheral endings of small-diameter primary afferent neurons play an important role in the inflammatory response, and that opioids are involved in the regulation of inflammatory response through the inhibition of SP release.

The present study demonstrates the distribution of nerve fibers containing calcitonin gene-related peptide (CGRP), substance P (SP), neurokinin A (NKA), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) in the hard palate mucosa and gingiva of the rat by the use of an indirect immunofluorescence method. Nerve fibers containing CGRP, SP and NKA showed very similar distribution patterns. Numerous nerve fibers containing CGRP, SP and NKA were observed in the lamina propria of hard palate mucosa. They formed dense subepithelial plexuses in incisive papilla and transverse palatine ridges. Some of them penetrated deeply into the epithelium and terminated as free nerve endings. In gingiva, nerve fibers containing these peptides were found especially near gingival sulcus. They were abundantly distributed beneath the junctional epithelium and formed nerve plexus. In all sampling regions, these nerve fibers were seen around the large- and medium-sized blood vessels in lamina propria and submucosal layer. NPY- and VIP-containing nerve fibers were observed in close association with blood vessels of hard palate mucosa. These nerve fibers were located around the large-sized blood vessels in the submucosal layer of hard palate and a few fibers were seen running along the small blood vessels in the lamina propria of the anterior half of hard palate mucosa. Nerve fibers containing these peptides were never found in gingiva.

Serum and salivary antibody responses to Bacteroides gingivalis fimbriae administered either orally or subcutaneously (s.c.) with or without an adjuvant in various strains of mice were examined in this study. Following results were obtained. 1) Oral administration of B. gingivalis fimbriae with GM-53 as an adjuvant in liposomes, but not in Tris-HCl buffer, definitely enhanced the fimbriae-specific IgG responses, mainly IgG1 followed by IgG2b, IgG2a and IgG3 in serum and IgA response in saliva of BALB/c mice. On the other hand, s.c. injection of fimbriae with GM-53 or MDP-Lys (L18) also raised the fimbriae-specific IgG followed by IgA and IgM responses in serum, and both IgA and IgG responses in saliva of BALB/c mice. Oral immunization was less effective than s.c. injection in terms of the production of serum antibody in the mice. However, the level of salivary antibody of mice injected s.c. was similar to that of mice immunized orally. 2) High anti-fimbriae antibodies in serum were maintained in BALB/c mice immunized orally with fimbriae and GM-53 in liposomes for approximately 7 months after the primary immunizations. Oral administration also induced and held the fimbriae-specific IgA response in saliva for at least 6 months after the primary immunizations. The levels of fimbriae-specific IgA in saliva after the second boosters on days 123 and 124 were higher than those after the primary ones on days 27 and 28. 3) Among various strains of mice immunized orally with fimbriae and GM-53 in liposomes, BALB/c and DBA/2 mice (H-2d) significantly produced high levels of both serum IgG and salivary IgA antibodies specific for fimbriae. Furthermore, B10.D2 mice (H-2d) were responders followed by B10.BR (H-2k), while C57BL/10 mice (B10, H-2b) were low responders to the fimbriae. These results show that the combined use of fimbriae together with an adjuvant results in a sharply increased IgA antibody response in saliva and a predominantly stimulated IgG antibody in serum, and it was suggested that these responses are restricted by H-2 haplotype.